After a standard system upgrade you need to reboot your computer toeffect the necessary changes.

ATTENTION: Due to an unavoidable ABI change for Ubuntu 8.04 and 8.10,the kernel updates have been given a new version number, which requiresyou to recompile and reinstall all third party kernel modules youmight have installed. If you use linux-restricted-modules, you have toupdate that package as well to get modules which work with the new kernelversion. Unless you manually uninstalled the standard kernel metapackages(e.g. linux-generic, linux-server, linux-powerpc), a standard systemupgrade will automatically perform this as well.

Details follow:

Igor Zhbanov discovered that NFS clients were able to create device nodeseven when root_squash was enabled. An authenticated remote attackercould create device nodes with open permissions, leading to a loss ofprivacy or escalation of privileges. Only Ubuntu 8.10 and 9.04 wereaffected. (CVE-2009-1072)

Dan Carpenter discovered that SELinux did not correctly handlecertain network checks when running with compat_net=1. A localattacker could exploit this to bypass network checks. Default Ubuntuinstallations do not enable SELinux, and only Ubuntu 8.10 and 9.04 wereaffected. (CVE-2009-1184)

Shaohua Li discovered that memory was not correctly initialized in theAGP subsystem. A local attacker could potentially read kernel memory,leading to a loss of privacy. (CVE-2009-1192)

Benjamin Gilbert discovered that the VMX implementation of KVM didnot correctly handle certain registers. An attacker in a guest VMcould exploit this to cause a host system crash, leading to a denialof service. This only affected 32bit hosts. Ubuntu 6.06 was notaffected. (CVE-2009-1242)

Thomas Pollet discovered that the Amateur Radio X.25 Packet Layer Protocoldid not correctly validate certain fields. A remote attacker could exploitthis to read kernel memory, leading to a loss of privacy. (CVE-2009-1265)

Trond Myklebust discovered that NFS did not correctly handle certainlong filenames. An authenticated remote attacker could exploit this tocause a system crash, leading to a denial of service. Only Ubuntu 6.06was affected. (CVE-2009-1336)

Oleg Nesterov discovered that the kernel did not correctly handleCAP_KILL. A local user could exploit this to send signals to arbitraryprocesses, leading to a denial of service. (CVE-2009-1337)

Daniel Hokka Zakrisson discovered that signal handling was not correctlylimited to process namespaces. A local user could bypass namespacerestrictions, possibly leading to a denial of service. Only Ubuntu 8.04was affected. (CVE-2009-1338)

Pavel Emelyanov discovered that network namespace support for IPv6 wasnot correctly handled. A remote attacker could send specially craftedIPv6 traffic that would cause a system crash, leading to a denial ofservice. Only Ubuntu 8.10 and 9.04 were affected. (CVE-2009-1360)

Neil Horman discovered that the e1000 network driver did not correctlyvalidate certain fields. A remote attacker could send a speciallycrafted packet that would cause a system crash, leading to a denial ofservice. (CVE-2009-1385)

Pavan Naregundi discovered that CIFS did not correctly check lengthswhen handling certain mount requests. A remote attacker could sendspecially crafted traffic to cause a system crash, leading to a denialof service. (CVE-2009-1439)

Simon Vallet and Frank Filz discovered that execute permissions werenot correctly handled by NFSv4. A local user could bypass permissionsand run restricted programs, possibly leading to an escalation ofprivileges. (CVE-2009-1630)

Jeff Layton and Suresh Jayaraman discovered buffer overflows in the CIFSclient code. A malicious remote server could exploit this to cause asystem crash or execute arbitrary code as root. (CVE-2009-1633)

Mikulas Patocka discovered that /proc/iomem was not correctlyinitialized on Sparc. A local attacker could use this file to crashthe system, leading to a denial of service. Ubuntu 6.06 was notaffected. (CVE-2009-1914)

Miklos Szeredi discovered that OCFS2 did not correctly handle certainsplice operations. A local attacker could exploit this to causea system hang, leading to a denial of service. Ubuntu 6.06 was notaffected. (CVE-2009-1961)